The present invention relates generally to a roller assembly of an undercarriage of a work machine, and more particularly to press fit roller assemblies of an undercarriage assembly of a work machine and method of making the same.
A work machine, such as a track-type tractor or excavator, is typically supported and propelled by a pair of undercarriage assemblies, each one of which includes an endless drive track chain having a plurality of interconnected articulating components or links. The undercarriage assembly typically also includes a drive sprocket, one or more idler wheels, a number of lower track rollers, and a carrier roller around each of which the drive track chain is entrained or otherwise advanced.
Over time as a result of extended operation of the work machine, a number of the components associated with the undercarriage assembly, such as the idler rollers, the track rollers, and the carrier roller begin to wear thereby necessitating repair thereof. However, repair of such components is often impractical since heretofore designed idler rollers, track rollers, and carrier rollers are generally mechanically complex thereby creating undesirable amounts of machine downtime during periods of repair. One such heretofore designed carrier roller is shown in U.S. Pat. No. 4,695,102 issued to Crotti. The carrier roller disclosed in Crotti, amongst other things, includes roller bearing assemblies for absorbing radial and axial thrust loads. However, use of such roller bearing assemblies adds to the mechanical complexity of the carrier roller thereby increasing the cost and time associated with repair thereof.
In an effort to avoid the complexity and cost associated with repair of idler rollers, track rollers, and carrier rollers, certain manufactures have chosen to make such components xe2x80x9cdisposablexe2x80x9d. In other words, when the component has worn to the point of needing repair, the idler roller, track rollers, or carrier roller is removed from the work machine and thereafter discarded. Thereafter, a replacement idler roller, track roller, or carrier roller is then installed on the machine. It should be appreciated that in the case of when a component is designed to be disposed, in lieu of repaired, it is even more desirable to produce the component in a cost efficient manner thereby reducing operation costs associated with the work machine.
What is needed therefore are undercarriage components which overcome one or more of the above-mentioned drawbacks. What is also needed are undercarriage components which are less mechanically complex relative to heretofore designed components. What is moreover needed is a method of manufacturing undercarriage components which is less expensive and less complex relative to heretofore utilized manufacturing methods.
In accordance with one embodiment of the present invention, there is provided a roller assembly for an undercarriage of a work machine. The roller assembly has a roller rim having central passage defined therein with (i) a first end of the central passage of the roller rim defining a first access opening, and (ii) a second end of the central passage of the roller rim defining a second access opening. The roller assembly also has a roller shaft having a first end portion which is positioned outside of the central passage of the roller rim and a second end portion which is positioned within the central passage of the roller rim, the second end portion of the roller shaft having an outwardly extending annular flange secured thereto. Yet further, the roller assembly has a retainer press fit into the second access opening. In addition, the roller assembly has an axial thrust bearing interposed between the outwardly extending annular flange of the roller shaft and the retainer.
In accordance with another embodiment of the present invention, there is provided a method of manufacturing a roller assembly for an undercarriage assembly of a work machine, with the roller assembly having (i) a roller rim which has central passage defined therein, with a first end of the central passage of the roller rim defining a first access opening and a second end of the central passage of the roller rim defining a second access opening, (ii) a roller shaft having a first end portion and a second end portion, the second end portion having an outwardly extending annular flange secured thereto, (iii) a retainer, and (iv) a thrust bearing. The method has the step of advancing the first end portion of the roller shaft through the second access opening of the central passage and out the first access opening of the central passage such that (i) the first end portion of the roller shaft extends out of the first access opening of the central passage, and (ii) the second end portion of the roller shaft is positioned in the central passage. The method also has the step of advancing the thrust bearing through the second access opening. Moreover, the method has the step of press fitting the retainer into the second access opening such that the thrust bearing is interposed between the retainer and the outwardly extending annular flange of the roller shaft.
In accordance with yet another embodiment of the present invention, there is provided a roller assembly for an undercarriage of a work machine. The roller assembly has a roller rim having a central passage defined therein with (i) a first end of the central passage of the roller rim defining a first access opening, and (ii) a second end of the central passage of the roller rim defining a second access opening. The roller assembly also has a roller shaft positioned in the central passage, the roller shaft having a first end portion which extends out of the first access opening of the central passage and a second end portion which extends out of the second access opening of the central passage. Moreover, the roller assembly has a first retainer press fit into the first access opening of the roller rim. The roller assembly further has a first collar press fit onto the first end portion of the roller shaft. In addition, the roller assembly has a first seal assembly interposed between the first retainer and the first collar.